Dictionary:

Mantinea

  (măn'tə-nē'ə)

An ancient city of southern Greece in the eastern Peloponnesus. Thebes defeated Sparta here in 362 B.C.

Mantinēa, small city-state in the south-east of Arcadia, north of Tegea, created by the unification of five villages c.500 BC. It was at first friendly to Sparta, but during the Peloponnesian War entered into alliance with Athens, Argos, and Elis (c.420). It was the scene of a decisive Spartan victory in 418 BC in a battle against Athenians and Argives. In the fourth century BC Mantinea was attacked by Sparta and broken up into villages (387–386). After the battle of Leuctra (371) the city was restored and took part in the pan-Arcadian confederacy founded at this time. It was the scene of another battle in 362 BC between Sparta and Thebes (in which Thebes was victorious but Epaminondas killed. Gryllus, the son of Xenophon, fighting with the Athenian contingent on the Spartan side, was killed in a cavalry engagement at Mantinea shortly before the main battle.

The noun has one meaning:

Meaning #1: the site of three famous battles among Greek city-states: in 418 BC and 362 BC and 207 BC
  Synonym: Mantineia